Every plant cell is surrounded by a wall, which is at the same time sufficiently strong to resist the turgor pressure and extensible to allow growth. Understanding how plants grow requires studying the architecture and the mechanical homeostasis of this polymer network. The objectives of HOMEOWALL are to combine cell biology, structural biology, soft matter physics and computational modeling to elucidate the nano- and mesoscale architecture of the plant cell wall, the phase transitions in wall polymers that underlie the growth process and the dual role of the recently discovered RALF/LRX/CrRLKL1 module in wall architecture and the control of the phase transitions in expanding cell walls. These data are expected to support a paradigm shift in the understanding of plant cell expansion and to provide new insights in the interactions between co-evolved polyelectrolytes, which are potentially of interest for the conception of new intelligent nanomaterials.